In a manufacturing process for a semiconductor device and an LCD substrate, a resist pattern is formed on a substrate by a technique referred to as “photolithography”. According to this technique, a series of processing is executed by applying a resist liquid over a substrate such as a semiconductor wafer (which will be referred to as a “wafer” hereinafter) to form a liquid film on a surface of the wafer, performing exposure on the resist film with a photomask and then performing developing processing to obtain a desired pattern.
The above processing of forming the resist pattern is performed by using a resist pattern forming device in which an exposing device is connected to an applying/developing device that generally performs resist liquid application and development.
FIG. 20 is a plan showing an example of a conventional resist pattern forming device.
Referring to FIG. 20, a conventional resist pattern forming device includes a carrier block 1A provided with a carrier stage 11 to and from which a carrier C accommodating twenty-five wafers W can be transferred, a processing block 1B, an interface block 1C and an exposing device 1D. Processing block 1B is provided at its central position with a transporting portion 12, and is also provided around transporting portion 12 with an application unit 13A for applying a resist liquid to the wafer, a liquid processing unit group including a plurality of developing units 13B and the like that are arranged in multiple levels for performing developing processing on the wafer subjected to the exposure, a heating unit for performing predetermined heat treatment on the wafer before and after the processing performed by the application unit and the developing unit, and shelf units 14 (14A-14C) provided with transferring units and the like. Carrier block 1A includes a transfer arm 15 that transfers a wafer W between carrier C and processing block 1B.
The heating unit is internally provided with a heating portion, and can perform predetermined heat treatment on wafer W by placing wafer W on a heating plate kept at a predetermined temperature. The heating unit performs several kinds of processing such as a pre-bake processing for evaporating a thinner in resist components, a post-exposure baking processing for relieving a fringe of a resist pattern, and a post-baking processing of removing a rinse liquid remaining after development by evaporating it or hardening the resist. The resist pattern forming device is provided with a plurality of heating units performing various kinds of processing.
The heating unit may have a heating plate divided into a plurality of heating zones that are independently heated by a plurality of concentric heaters, respectively. In this case, it is necessary to uniformize temperature rising patterns of the respective heating zones for ensuring in-plane uniformity in film thickness and developing line width. Also, it is necessary to uniformize the temperature rising patterns of the heating plates performing the same processing for ensuring the uniformity in film thickness and developing line width of the heating units. Therefore, at the time of startup of the device or periodically, processing is performed to determine temperature characteristics of the heating plates of the heating units and uniformize the temperature rising patterns of the heating zones, and the heating portions in the heating units performing the same processing are controlled to ensure the same temperature rising pattern.
FIG. 21 is a perspective view showing a wafer for temperature measurement of the heating plate.
Conventionally, the temperature characteristics of the heating plate are measured by such an operation that wafer W provided at its surface with forty temperature sensors is placed on the heating plate, and the temperature is measured at intervals of a predetermined time. In this case, as illustrated in FIG. 21, temperature sensors 16 must be connected by serial cables 18 to a measuring device 17 that is arranged outside wafer W for storing temperature data provided from each temperature sensor 16.
For measuring the temperature characteristics of the heating plate, it is necessary to remove a rear cover of the resist pattern forming device, to place wafer W bearing temperature sensors 16 on the heating plate and to connect temperature sensors 16 to measuring device 17 arranged outside wafer W by serial cables 18. As described above, the read cover of the device must be opened every time the temperature characteristics of the heating plate are to be measured, which results in an inconvenient handling. When heat is discharged due to opening of the cover, a wait time will be required until the temperature inside the heating unit becomes stable after closing the cover. In the conventional resist pattern forming device, the above operation is required for each heating unit so that the sum of the above wait times may exceed 20 hours.
In view of the above, the inventors are making a study for temperature measurement with a wireless wafer that does not require serial cables extending externally from wafer W. This wireless wafer is provided at itself with a temperature sensor, a battery, a memory and a controller, and is configured to save temperature data in the memory at intervals, e.g., of one second. A technique in Japanese Patent Laying-Open No. 11-307606 (Patent Document 1) has been known as a manner of evaluating uniformity in substrate temperature during heat treatment with the above type of wafer.
Patent Document 1: Japanese Patent Laying-Open No. 11-307606